This project is a multi-institutional Phase I evaluation of the ability to heat tumors in each of the major anatomic sites (brain, head and neck, lung, mediastinum, upper abdomen, pelvis, superficial and deep lymph nodes, trunk, and extremities) with "state of the art" heat generating and thermometry systems. Institutions with expertise in the equipment for clinical hyperthermia will be provided limited additional equipment to conduct a systematic investigation of the advantages and disadvantages of each hyperthermia system for heating tumors in the major anatomic sites.